Re: Call Library Function & DLL Attach and Detach Calls
- From: rolfk <x@xxxxxxxx>
- Date: Fri, 14 Jul 2006 04:10:08 -0500 (CDT)
Tomi M wrote:I used the code below.#include <iostream>#include <fstream>BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved ){ using namespace std; ofstream out("C:\log.txt", ios::app); switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH: out << "DLL_PROCESS_ATTACH" << endl; break; case DLL_THREAD_ATTACH: out << "DLL_THREAD_ATTACH" << endl; break; case DLL_THREAD_DETACH: out << "DLL_THREAD_DETACH" << endl; break; case DLL_PROCESS_DETACH: out << "DLL_PROCESS_DETACH" << endl; break; } return TRUE;} TomiLabVIEW
simply uses LoadLibrary() to load a shared library into memory. It has
no direct control of how Windows will initialize that DLL inside the
LoadLibrary() function. It may be that the DLL is already loaded
somewhere, somehow or that Windows decides that it needs not to
initialize the DLL anymore. As to why and how this could happen you
would be better of asking MS or some low leverl Windows API guru, not
NI.
Have you tried to create a test app that loads your DLL with
LoadLibrary() and frees it afterwards with FreeLibrary() to see how it
works there? Unless you can proof that it is different there, there is
absolutely no use in trying to investigate an issue in LabVIEW of which
you don't even know if it is somehow LabVIEW related. The multiple
PROCESS_DETACH might be related to multiple FreeLibary() calls by
LabVIEW in different situations to make sure the DLL is always properly
purged. Windows has a somewhat strange refcount for DLL loads that can
lead especially in multi-threading applications to the situation that
eventhough you matched every LoadLibrary() call with a FreeLibrary()
call, the DLL still remains in memory until the parent process
completely terminates.
Rolf Kalbermatter
.
- Prev by Date: Re: Timeout error in TCP Read
- Next by Date: Re: how to disable/restore network(LAN) I/O port ?
- Previous by thread: Re: Call Library Function & DLL Attach and Detach Calls
- Next by thread: The conversion of rectangle dimensions
- Index(es):
Relevant Pages
|
